Conventionally, known is technology concerning stereoscopic viewing as a method of obtaining a three-dimensional visual sensation by using parallax. In recent years, representation based on this kind of stereoscopic viewing is being used in various fields. For example, by using representations based on stereoscopic viewing, games and CG (Computer Graphics) animation and the like which stereoscopically display a three-dimensional virtual space are being developed.
When stereoscopically displaying a three-dimensional virtual space, for example, images obtained from two virtual cameras set within the three-dimensional virtual space are used. In order to realize stereoscopic viewing with a high visual effect, the foregoing two virtual cameras need to be set appropriately. For example, known is a setting method of virtual cameras for deciding the gaze position so as to focus attention at the portion to be observed (refer to Japanese Patent Application Laid-open No. 2003-107603).
With the technology of conventional stereoscopic viewing, when generating an image for stereoscopic viewing (hereinafter also referred to as the “stereoscopic image”), for example, the gaze position is decided to be a specific object in the virtual space. Thus, with the technology of conventional stereoscopic viewing, attention was focused only on a specific object, and it was difficult to enable the user to appropriately comprehend the virtual space that is represented by stereoscopic images.